The present invention generally relates to a control apparatus for controlling position of a table or a bed for supporting an object or patient under inspection lying thereon in a medical diagnosis system such as an X-ray diagnosis system, X-ray computerized tomography system (hereinafter referred to as the X-ray CT system), magnetic resonance imaging (MRI) system and the like. More specifically, the invention is concerned with a table control apparatus for a medical diagnosis system which is designed for controlling movement or displacement of the table supporting a person under inspection lying thereon for the purpose of positioning an affected part of the person or for other purposes.
In the X-ray CT system which is a typical one of the medical diagnosis systems, inspection or diagnosis is performed in the state in which a patient (i.e., a person undergoing medical inspection, diagnosis or the like) is lying on a table. In order to carry out effectively the inspection or diagnosis and/or treatment, such a table positioning control is required that an electric motor constituting a driving power means for moving the table is driven under remote control, to thereby move or displace the table to a position close to an X-ray CT scanner carrying an X-ray tube, an X-ray detector, etc. In this conjunction, it is noted that such a combined procedure is often adopted in which inspection and treatment are carried out at a same time by combining the X-ray CT system and a circulatory organ X-ray inspection system capable of angiographic inspection because of a trend of the interventional radiography (IVR in abbreviation) such as e.g. transcatheter arterial embolization being increasingly conducted in recent years. In such combination system, it is desirable that one and the same table for supporting the person undergoing the inspection and the treatment in a lying state can be used for both the X-ray CT diagnosis and the angiographic treatment in order to allow the diagnosis and the treatment to be carried out consistently in continuation. Under the circumstances, there arises a demand for the table for the combination diagnosis system which is imparted with not only the function suited for the X-ray CT diagnosis but also the function proper to the angiographic treatment. Parenthetically, the table for the medical diagnosis system is required to ensure high-speed positioning with high accuracy, while the table for the angiographic inspection or treatment system is required to allow floating operation freely in two-dimensional directions.
The conventional table structure for the angiographic inspection or treatment can be manipulated by operator's hand freely in X- and Y-directions for carrying out the angiographic inspection or surgical operation. However, because of a large scale mechanism incorporated in the table structure, high load is encountered in manipulating the table, requiring a large manipulating force. Thus, the table for the angiographic treatment suffers a problem that the table is not easy to use for the interventional radiology which requires a fine or delicate positioning manipulation. Further, the conventional table control apparatus for the X-ray CT diagnosis is designed to satisfy the positioning control required in the X-ray CT diagnosis. In other words, in the conventional table control apparatus for the X-ray CT diagnosis, it is practically impossible to perform fine or delicate operation for moving the table to a given position desired by the operator by a hand required for manipulation of the interventional radiology.
Furthermore, in the apparatus for manually operating the table, a large manipulating force is required because of a load imposed additionally by weight of the patient. Besides, difficulty is encountered in stopping the table accurately at a desired position due to the influence of the inertial force. Thus, the conventional table control apparatus is not always easy to operate or manipulate.